Reflection, Refraction and Diffraction

Lab Brief #3

🎯 Your mission

Run the experiment. Find out what really happens.

⚡ The twist

Nature loves to surprise the careful watcher.

What you'll learn

Waves reflect off barriers with the angle of incidence equal to the angle of reflection. They refract — change direction — when their speed changes at a boundary. They diffract, spreading out, when they pass through a gap comparable to their wavelength.

Key words

refraction
The change of direction of a wave when its speed changes at a boundary.
diffraction
The spreading of a wave as it passes an edge or through a gap.

Make a hypothesis first

Before you start: write down what you think will happen, and why.

Say your guess out loud — then find out if you were right.

Get ready

🧰 What you need

ripple tank
barriers
glass plate
lamp
water

Get ready

⚠️ Safety first

Keep the lamp and its cable clear of the water.
Wipe up spills at once.

Step 1 of 4 · Read

Think about what you just learned: say what "refraction" and "diffraction" mean in your own words before you start.

Step 2 of 4 · Do

In a ripple tank, place a straight barrier for reflection, a shallow glass plate for refraction, and two barriers forming an adjustable gap for diffraction. Sketch the wavefronts in each case and vary the gap width.

Step 3 of 4 · Observe

Record what actually happened, including anything that did not match what you expected.

Step 4 of 4 · Record

Write a conclusion that answers the question this lesson opened with, and state your uncertainty.

Question 1 of 2

Diffraction is most pronounced when the gap width is:

How sure are you?😐 maybe

Question 2 of 2

Refraction happens because the wave changes its:

How sure are you?😐 maybe

Mind = blown

🔬 The more you look, the more nature shows you.

Nice work!

You got 0 of 2 right.

Next: Amplitude, Intensity and Energy All lessons

🎯

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✨ More to explore

🌍 Where you see this in real life: This shows up in your everyday life more than you'd think.

🏆 Stretch challenge (try it this week): Try one experiment in real life this week — even a tiny one.

👨‍👩‍👧 For the dinner table: “What's the most surprising thing you learned today?”

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